System and method for identifying errors in a video conference conducted on a packet-based network

ABSTRACT

A system and method for identifying errors in a video conference conducted on a network are disclosed. A central device includes a central agent that detects an error during a video conference conducted on a network between two or more endpoints. The central agent distributes a capture agent via the network to a remote device associated with a collision domain that contains one of the two or more endpoints. The capture agent collects a plurality of media packets associated with the video conference in a capture file located in a storage medium associated with the remote device until a timer expires. When the timer expires, the capture agent communicates the capture file to the central agent at the central device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication Ser. No. 60/309,135, filed Jul. 31, 2001, and entitled“System and Method for Identifying Errors in a Video ConferenceConducted on a Network.”

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to video conferencing, and moreparticularly to a system and method for identifying errors in a videoconference conducted on a packet-based network.

BACKGROUND OF THE INVENTION

Today, people can communicate with each other through a variety ofmethods. Meetings between two or more individuals located at physicallydistinct locations may be conducted on a telephone and through videoconferences. Video conferencing allows individuals at remote locationsto interact and exchange information through electronic means. A videoconference typically includes full motion video presentations that areconducted across any number of communications networks and displayed onvideo conferencing systems located at the remote locations. The videoconferencing systems generally include a camera and a microphone tocapture the video and audio information at the particular location, amonitor that allows the participants at one location to view and hearthe participants at the remote location and a computer device thatprocesses the audio and video information that is transmitted andreceived by the endpoint.

Each video conference occurring over a particular network may bemonitored by a system or network administrator. The administratortypically is not physically located near any of the endpointsparticipating the video conferences. The administrator may monitor thevideo conferences occurring on a particular network but has no way ofremotely determining whether network factors, such as jitter, latencyand throughput, are causing the decrease in quality of the audio andvideo streams in the conference. Therefore, it is practically impossiblefor the administrator to make a real-time determination whether thenetwork factors are the root cause of the poor audio and/or videoquality experienced by the users, or whether the network is operatingbeyond thresholds that would make poor audio and video quality a likelyresult.

Furthermore, video conferencing systems are typically distributed overlarge geographic areas and video conferences typically occur between twoor more locations that are remote to the administrator. In order todiagnose some problems that may be related to the network, anadministrator must travel to the remote locations or a skilled networkprofessional must be located at each one of the remote sites. Theadministrator can then determine if latency, jitter and throughput arecausing the decrease in quality in the audio and video streams.

SUMMARY OF THE INVENTION

Therefore a need has arisen for a system and method that automaticallymonitors a video conference conducted over a network and identifiesproblems in the network that cause errors during the video conference.

A further need exists for a system and method that provides real-timeanalysis of whether network parameters are the cause of poor audioand/or video quality in the video conference.

An additional need exists for a system and method that automaticallydistributes an agent via a network to the remote locations of a videoconference and calculates the latency, jitter and throughput of atypical video conference for analysis by a system administrator.

In accordance with the present invention, a system and method isprovided that substantially eliminates the disadvantages and problemsassociated with previously developed systems and methods for identifyingerrors in a video conference conducted on a network. A distributed agentcollects media packets transmitted and received by one or more endpointsparticipating in a video conference and communicates the collected mediapackets to a central agent. The central agent analyzes the media packetsto determine if network factors caused an error to occur in the videoconference.

More specifically, a central agent at a central device remotely monitorsa video conference between two or more participating endpoints. Thecentral agent distributes a capture agent that examines individualpackets to determine values for network parameters, such as jitter,latency, throughput and packet loss. The central agent distributes thecapture agent at the request of a system administrator, at timeintervals determined by the administrator, or based on conditions in thenetwork that generate an alarm. The conditions that generate the alarmmay be triggered by Simple Network Management Protocol (SNMP) or othersuitable monitoring techniques that may be included in the centralagent, or by external network management systems, according tothresholds defined by the administration.

When notified, the central agent distributes a capture agent to a remotedevice associated with a collision domain that contains one of theendpoints participating in the video conference. After distributing thecapture agent, the central agent initiates a timer that controls howmuch information is collected during the video conference. For example,the timer could be set to expire after a predetermined amount of time ora predetermined number of packets are collected, or the timer couldexpire at the end of the video conference.

Once the timer has started, the capture agent monitors the videoconference and collects media packets transmitted and received by theparticipating endpoints. The capture agent stores the media packets in acapture file located in a storage medium interfaced with the remotedevice. When the timer expires, the capture agent communicates thecapture file from the remote device to the central device. The centralagent reads the capture file and analyzes the collected media packets todetermine what network parameter caused the error in the videoconference. For instance, the media packets may include real-timeprotocol (RTP) and real-time control protocol (RTCP) packets. Thecentral agent examines the time stamp on the collected media packets andthe sequence number of the packets to determine the latency for themedia packets and the amount of jitter present in the video conference.

After analyzing the media packets in the capture file, the central agentdisplays the results on a graphical user interface (GUI). The systemadministrator uses the results to determine if the network conditionscaused the errors in the video conference. In an alternative embodiment,the central agent automatically sends an alarm to the systemadministrator if the measured values for latency, jitter and/orthroughput exceed the thresholds defined by the administrator.

The present invention provides a number of important technicaladvantages. One important technical advantage of certain embodiments ofthe present invention includes a central agent that monitors traffic ona network and provides real-time analysis of errors that may occurduring a video conference. Upon receiving notification, the centralagent automatically distributes a capture agent to the endpointsparticipating in the video conference. The capture agent collects mediapackets transmitted and received by the endpoints and communicates thepackets to the central agent to be decoded and analyzed. Thus, a systemadministrator can receive a report on problems that occur on the networkand can correct those problems before the audio and/or video quality ofthe video conference degrades.

An additional technical advantage of certain embodiments of the presentinvention includes a central agent that provides passive collection ofnetwork information. A system administrator determines threshold valuesfor various network parameters. When one of the threshold values isexceeded, the central agent receives an alarm and distributes a captureagent to the endpoints participating in a video conference. The captureagent is opened and executed by a remote device associated with theendpoints. Therefore, network traffic is not significantly increasedbecause the central agent and the capture agent collect and analyzeinformation from devices coupled to the network.

A further technical advantage of certain embodiments of the presentinvention includes a central agent that provides reports to a systemadministrator so that problems in a network may be corrected before anerror occurs in a video conference. A central agent receives a file froma capture agent that includes multiple media packets from one videoconference being conducted on the network. The central agent decodes themedia packets and calculates specific network parameters, such aslatency, jitter and throughput. The system administrator may use theseparameters to analyze the network traffic and prevent the reportedproblems from affecting future video conferences.

Other technical advantages will be readily apparent to one skilled inthe art from the following figures, descriptions, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention and advantagesthereof may be acquired by referring to the following description takenin conjunction with the accompanying drawings, in which like referencenumbers indicate like features, and wherein:

FIG. 1 illustrates a block diagram of a video conferencing system thatidentifies errors in a video conference conducted over a network betweentwo or more endpoints;

FIG. 2 illustrates a block diagram of an endpoint that identifies errorsin the video conference conducted over the network; and

FIG. 3 illustrates a flowchart of a method for identifying errors in thevideo conference conducted over the network.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention are illustrated in thefigures, like numerals being used to refer to like and correspondingparts of the various drawings.

Video conferencing between two or more remote locations is becoming apopular way of allowing individuals to communicate with each other.Businesses often prefer the more personal communication availablethrough a video conference when compared to a telephone conference, andalso can save travel costs while having a personal presence among theparties that is not possible with a telephone conference. However, theaudio and video quality of the video conferences may be degraded byproblems in the network. For example, if latency or jitter exceed anacceptable threshold, glitches may occur in the video conference thatcause the audio to be out of synch with the video or the video mayfreeze and lose part of the conference.

Currently, system administrators have no way of remotely identifyingpotential network errors related to latency, jitter and/or throughput inreal-time. In one embodiment, the present invention allows real-timeidentification of the errors in a video conference by distributing acapture agent to the endpoints participating in the video conferencewhen a network error is detected. The capture agent collects mediapackets from each participating endpoint and communicates them to acentral agent when a timer set by the central agent expires. The centralagent analyzes the media packets and displays the results on a graphicaluser interface (GUI) to allow the system administrator to determine ifthe network is the cause of the errors in the video conference.

FIG. 1 illustrates a block diagram of video conferencing system 10 foridentifying errors during a video conference conducted over network 12.Although a specific network is illustrated in FIG. 1, the term “network”should be interpreted as generically defining any network capable oftransmitting telecommunication signals, data and/or messages. In theillustrated embodiment, system 10 includes routers 26 a and 26 b(generally referred to as routers 26) coupled to network 12 and switches24 a and 24 b (generally referred to as switches 24) coupled to routers26. Endpoints 14 a through 14 d (generally referred to as endpoints 14)and endpoints 16 a through 16 d (generally referred to as endpoints 16)respectively couple to switches 24 a and 24 b. System 10 furtherincludes central device 18 and central client 20 coupled to switch 24 aand remote device 22 coupled to switch 24 b. In one embodiment, centraldevice 18 includes a central agent that distributes a capture agent toone or more of endpoints 14 and 16 and/or remote device 22 uponreceiving notification that an error occurred in a video conferencebeing conducted over network 12. The capture agent collects mediapackets transmitted and received by endpoints 14 and 16 during the videoconference and communicates the media packets to the central agent foranalysis when a timer expires or the affected video conference ends.

Network 12 may be a local area network (LAN), a wide area network (WAN),the Internet or other suitable network that transmits packets of voice,video, data and other information (generally referred to as media). In aparticular embodiment, network 12 may be an Internet Protocol (IP)network. However, network 12 may be any type of network that allowstransmission of audio and video telecommunication signals, as well astraditional data communications. Therefore, although subsequentdescription will primarily focus on IP communications, it should beunderstood that other appropriate methods of transmitting media over anetwork, such as a Frame Relay, Asynchronous Transfer Mode (ATM) orother packet-based networks, are also included within the scope of thepresent invention.

IP networks and other packet-based networks typically transmit media byplacing the data in cells, packets, frames, or other portions ofinformation (generally referred to as packets) and sending each packetindividually to the selected destination. Unlike a circuit-switchednetwork, such as Integrated Services Digital Network (ISDN), dedicatedbandwidth is not required for the duration of a conference call overnetwork 12. Instead, endpoints 14 and 16 may send packets across network12 as network 12 becomes available for transmission. This feature makesbandwidth available for additional communications when endpoints 14 and16 are not communicating media.

Endpoints 14 and 16 may be any type of video conferencing systems thatprovides real-time audio and video communication to users at remotelocations. Endpoints 14 and 15 may have the capability to encapsulate auser's voice, the user's image and/or other content into data packets sothat the content may be transmitted over network 12. Endpoints 14 and 16may also have the capability to communicate video information overnetwork 12 by using H.323 or any other suitable video communicationprotocol and audio information by using G.711, G.723, G.729 or othersuitable audio coding protocols. In an alternative embodiment, endpoints14 and 16 may, for example, include cordless or cellular telephones,personal digital assistants (PDAs), or other wireless devices. Also,endpoints 14 and 16 may include telephony software running on acomputing device, traditional plain old telephone (POTS) devices, analogphones, digital phones, IP telephony devices, or other computing and/orcommunication devices that communicate media using analog and/or digitalsignals.

Routers 26 are linked to switches 24 and network 12 by any suitablephysical transmission media and/or communications equipment. Routers 26may represent communications equipment, including hardware and/orsoftware, operable to receive, route and transmit packets ofinformation. Routers 26 may include one or more interfaces through whichthe services provided by routers 26 may be accessed by other devices onnetworks 12. Routers 26 may also include an operating system thatprovides routing services through the implementation of various routingprotocols, quality of service (QoS) services, and discovery services.Routers 26 further define the boundary of the broadcast domainassociated with endpoints 14 and 16. The broadcast domain defines theportion of the network that switches 24 control.

In the illustrated embodiment, central device 18 couples to switches 24and is located in one of the broadcast domains associated with endpoints14 and 16. In an alternative embodiment, central device 18 may belocated at any position in network 12. Central device 18 includes acentral agent that monitors network 12 through standard networkmanagement techniques, such as Simple Network Management Protocol(SNMP), to determine if certain network parameters exceed a predefinedthreshold defined by a system administrator. The central agent mayinitiate distribution of the capture agent according to time intervalsdetermined by the system administrator, on a request from theadministrator, when a network threshold set by the administrator hasbeen met or exceeded, or any other suitable technique for triggering thedistribution of the capture agent during a video conference.

Once the capture agent has been distributed, it measures networkparameters, such as latency, jitter, and throughput. Latency refers tothe time between transmission of a media packet at endpoint 14 a toreception of the media packet at endpoint 16 b. Latency may be increasedif traffic over network 12 increases. In one embodiment, thepredetermined threshold may be approximately 250 milliseconds. Jitter isthe variation in latency that results from media packets arriving attheir destinations (e.g., endpoints 14 a or 16 b) at different times.These media packets may arrive in a different sequence and cause pooraudio and video quality if the media packets are dropped. Endpoints 14 aand 16 b include buffers that store media packets for a specific lengthof time and assemble the media packets in the correct order. If thejitter exceeds the buffer storage time, the media packets will bedropped, and endpoints 14 a and 16 b may lose the ability to maintainsynchronization between the audio stream and the video stream of thevideo conference and frames of the video conference may freeze.Throughput is the amount of data traffic that can be sent and receivedover network 12 in a given time interval. If the throughput drops belowa certain time interval, the amount of audio and video information willdecrease, which increases the amount of latency. Decreased throughputand increased latency may result in the degradation in quality of theaudio and video information in the video conference.

If the central agent receives a distribution notice, the central agentdistributes a capture agent to remote device 22 to collect media packetsassociated with the video conference being measured. The capture agentreturns the collected media packets to the central agent at centraldevice 18 to be decoded and analyzed. Results are displayed on centralclient 20 where the system administrator can determine how to correctthe problems in the video conference. Central client 20 may be aworkstation, desktop computer, server or any other computer system thatincludes a display or GUI that allows a user to view and manipulatedata.

Remote device 22 includes processing resources and an associated storagemedium (not expressly shown). The processing resources may be acontroller, microprocessor, digital signal processor (DSP) or othersuitable device that may execute the capture agent to collect mediapackets during the video conference. The storage medium may beintegrated in or interfaced with remote device 22 and operates to storethe collected media packets in a storage file for communication back tothe central agent located on central device 18. Although FIG. 1 showsremote device 22 as being separate from endpoints 14 and 16 in FIG. 1,remote device 22 and endpoints 14 and 16 may each operate on one or morecomputers at one or more localized or distributed locations throughoutnetwork 12. In an alternative embodiment, remote device 22 may belocated on one of the switch ports in switches 24 that have thecapability to monitor the traffic for endpoints 14 and/or 16.

In operation, the processing resources located in remote device 22execute the capture agent to collect media packets during the videoconference. The processing resources store the collected packets in thecapture file located in the storage medium. When a timer started by thecentral agent expires, the processing resources retrieve the capturefile from the storage medium and communicate the file back to thecentral agent being executed on central device 18.

FIG. 2 illustrates a block diagram of endpoints 14 and 16 that identifyerrors in a video conference conducted on network 12. Endpoints 14 and16 may include network interface 30, processing resources 32 and storagemedium 34. Network interface 30 operates to couple endpoints 14 and 16to network 12 so that endpoints 14 and 16 may participate in a videoconference. Processing resources 32 may be a controller, amicroprocessor, a DSP, or any other suitable resource that executes anagent for monitoring a video conference, and collecting and analyzingmedia packets associated with the video conference. Storage medium 34may be any type of storage device that is capable of storinginformation, such as media packets containing audio, video, and/or datainformation.

In operation, media packets associated with the video conference aretransmitted and received through network interface 30. Processingresources 32 interface with network interface 30 and execute a captureagent that collects the transmitted and received media packets. Whileexecuting on processing resources 32, the capture agent communicateswith storage medium 34 to store the collected media packets in a capturefile. When the capture agent receives notification that a timerassociated with the video conference has expired, processing resources32 retrieve the capture file from storage medium 34 and communicates thefile to a central agent via network interface 30. In an alternativeembodiment, processing resources 32 retrieve the capture file, decodethe collected media packets, and analyze the video, audio, and datainformation contained in the media packets. The results of the analysismay include the latency for the media packets communicated in the videoconference, the jitter associated with the video conference, the numberof packets dropped or lost during the video conference and thethroughput of network 12. Processing resources 32 then send the resultsto the central agent via network interface 30.

FIG. 3 illustrates flowchart for identifying errors in a videoconference conducted on network 12. Generally, a central agent locatedon central device 18 monitors network 12 using standard networkmanagement techniques, such as SNMP, and determines when predefinedthresholds have been met or exceeded. When the central agent receivesnotification of a potential network error or that a predefined timeinterval has elapsed, or a system administrator manually sends arequest, the central agent distributes a capture agent to endpoints 14and 16 and/or remote device 22. The capture agent collects media packetstransmitted and received by endpoints 14 and 16 and stores the packetsin a capture file. When the video conference ends or a timer started bythe central agent expires, the capture agent communicates the capturefile back to the central agent for analysis. The central agent decodesand analyzes the media packets, and displays the results on clientdevice 20 for a system administrator. If the central agent determinesthat the latency, jitter, throughput, packet loss, or other relevantnetwork parameters associated with the video conference exceedthresholds defined by the system administrator, an alarm may also besent to the administrator.

As shown at step 40, a video conference may be established betweenendpoint 14 a and endpoint 16 b over network 12. Although a videoconference between endpoints 14 a and 16 b will be described indetailed, it should be understood that a video conference could occurbetween any one or more of endpoints 14 and any one or more of endpoints16. In an alternative embodiment, the same principles described belowmay also be applied to a telephone conference occurring betweentelephony devices coupled to network 12. At step 42, a central agentlocated at central device 18 monitors network 12 for potential problems.In one embodiment, the central agent is notified of a possible error byan alarm. The alarm indicates that a network parameter, such as an SNMPvalue in a router, has exceeded and/or dropped below a predeterminedthreshold. In another embodiment, notification of an error may beprovided by a user at one of endpoints 14 a and 16 b. The user may use atelephone or send an electronic message over network 12 to the systemadministrator at client device 20. The system administrator may manuallyinitiate the monitoring of jitter, latency, throughput, packet lossand/or other relevant network parameters for the video conferenceassociated with the user. In a further embodiment, the central agent maydistribute the capture agent automatically according to a time intervaldesignated by the administrator.

If the central agent does not receive a request to monitor network 12 inorder to measure the relevant network parameters in a video conference,the central agent continues to monitor network 12 with standard networkmanagement tools, such as SNMP tools, at step 42. If the central agentdoes receive a request to monitor network 12, either by a network alarm,an instruction from the system administrator, or according to apredefined time interval, the central agent distributes a capture agentto one or both collision domains that contain endpoints 14 a and 16 b atstep 44. Once the capture agent is distributed to the collision domains,it may be executed on either or both of endpoints 14 a and 16 b, orremote device 22 may host the capture agent in the collision domainassociated with endpoint 16 b. In the illustrated embodiment, remotedevice 22 is located in the collision domain that contains endpoint 16 band may monitor any network traffic transmitted or received by endpoint16 b. In an alternative embodiment, remote device 22 may be located on aswitch port on switch 24 b that has the capability to monitor anytraffic communicated to and/or from endpoint 16 b.

When the capture agent is being distributed to endpoints 14 a and 16 band/or remote device 22, the central agent starts a timer that isassociated with the video conference at step 46. In one embodiment, thetimer may be set to expire when the video conference ends. In analternative embodiment, the timer may be set to expire after apredetermined amount of time has elapsed. In this example, if the videoconference ends before the timer expires, the default for the timer isthe end of the video conference. In a further embodiment, the timer maybe set to collect a predetermined number of media packets. If theminimum amount of media packets is not collected, the capture agentattempts to generate results from the media packets that were collectedduring the length of the video conference.

After the timer is started, the distributed capture agents collect mediapackets that are transmitted and received by endpoints 14 a and 16 b atstep 48. The media packets may include audio, video and/or datainformation. In one embodiment, network 12 may support communicationusing the RTP and RTCP, or any suitable protocol for transportingreal-time data, such as audio or video, over network 20. RTP providesend-to-end delivery services for packets of media. In this example, themedia packets include time stamps based on the time that the mediapackets were transmitted from one of endpoints 14 a or 16 b and sequencenumbers that indicate the sequence in which the media packets should beassembled at the receiving endpoint. At step 50, the capture agentstores the collected media packets in a capture file that is located ona storage medium associated with either remote device 22 or endpoints 14a or 16 b.

At step 52, the capture agent determines if the timer has expired. Ifthe timer has not expired, the capture agent continues to collect mediapackets at step 48 and store the media packets in the capture file atstep 50. If the timer has expired, the capture agent communicates thecapture file containing the collected media packets to the central agentlocated on central device 18 at step 54. Upon receiving the capturefile, the central agent decodes the media packets and calculates networkparameters, such as latency, jitter, throughput packet loss, or otherrelevant network parameters, for network 12 during the video conferenceat step 56. In one embodiment, the central agent displays the calculatednetwork parameters on a display coupled to central client 20 for thesystem administrator. In another embodiment, the central agent alertsthe administrator when a value for jitter, latency, throughput, packetloss, and/or other relevant network parameters exceeds a predefinedthreshold by using an alarm. The system administrator may use theresults or alarm to determine if the poor video and audio quality iscaused by the network and troubleshoot the problems in real-time ratherthan having to travel to the physical location of either of endpoints 14a or 16 b. In an alternative embodiment, the capture agent may performthe analysis of the media packets and communicate the results to thecentral agent for display on central device 20.

Although the present invention has been described with severalembodiments, a myriad of changes, variations, alterations,transformations, and modifications may be suggested to one skilled inthe art, and it is intended that the present invention encompass suchchanges, variations, alterations, transformations, and modifications asfall within the scope of the appended claims.

1. A method for identifying errors in a video conference conducted on apacket-based network, comprising: receiving a request to monitor thenetwork during the video conference conducted between two or moreendpoints; distributing a capture agent over a network from a centralagent at a central device to a remote device in response to the request,the remote device associated with a collision domain that contains oneof the two or more endpoints and operable to execute the capture agent;collecting a plurality of media packets associated with the videoconference in a capture file until a timer expires, the capture filelocated in a storage medium interfaced with the remote device; andcommunicating the capture file from the remote device to the centraldevice when the timer expires.
 2. The method of claim 1, furthercomprising analyzing the media packets at the central device todetermine one or more network parameters that caused an error in thevideo conference.
 3. The method of claim 2, further comprising thenetwork parameters selected from the group consisting of latency,jitter, throughput, and packet loss.
 4. The method of claim 1, whereinthe timer expires at the end of the video conference.
 5. The method ofclaim 1, further comprising the remote device located on a switch portassociated with the collision domain, the switch port operable tomonitor network traffic between the two or more endpoints within thecollision domain.
 6. The method of claim 1, further comprising:distributing the agent from the central device to two or more remotedevices respectively associated with the two or more endpoints, the twoor more remote devices respectively located in two or more broadcastdomains; and storing the media packets in two or more storage mediumsrespectively interfaced with the two or more remote devices until thetimer expires.
 7. The method of claim 1, wherein the media packetscomprise real time protocol (RTP) packets and real time control protocol(RTCP) packets.
 8. The method of claim 1, wherein the network comprisesan Internet Protocol (IP) network, an Asynchronous Transfer Mode (ATM)network or a Frame Relay network.
 9. The method of claim 1, wherein themedia packets comprise audio information.
 10. The method of claim 1,wherein the media packets comprise video information.
 11. The method ofclaim 1, wherein the media packets comprise data information.
 12. Themethod of claim 1, wherein receiving the request comprises receivingnotification of a potential error in the network through an alarmgenerated by the central agent.
 13. The method of claim 1, whereinreceiving the request comprises determining that a distribute timer hasexpired.
 14. The method of claim 1, wherein receiving the requestcomprises initiating the distribution of the capture agent by a systemadministrator at the central device.
 15. An apparatus for identifyingerrors in a video conference conducted on a packet-based network,comprising: an interface operable to couple to the network; a storagemedium; and a processing resource coupled to the storage medium and theinterface, the processing resource operable to execute a capture agentreceived over the network from a central agent located at a centraldevice and operable to: collect a plurality of media packets associatedwith the video conference conducted on the network between two or moreendpoints in response to a request to monitor the network, the requestreceived by the central agent; store the media packets in the storagemedium until a timer expires; and communicate the media packets to thecentral device via the interface when timer expires.
 16. The apparatusof claim 15, further comprising the capture agent operable to analyzethe media packets to determine one or more network parameters thatcaused an error during the video conference.
 17. The apparatus of claim16, further comprising the network parameters selected from the groupconsisting of latency, jitter, throughput, and packet loss.
 18. Theapparatus of claim 15, wherein the media packets comprise audioinformation.
 19. The apparatus of claim 15, wherein the media packetscomprise video information.
 20. The apparatus of claim 15, wherein themedia packets comprise data information.
 21. The apparatus of claim 15,wherein the media packets comprise real time protocol (RTP) packets andreal time control protocol (RTCP) packets.
 22. The apparatus of claim15, wherein the timer expires after a predetermined amount of time, thepredetermined amount of time calculated by the central device.
 23. Theapparatus of claim 15, wherein the network comprises an InternetProtocol (IP) network, an Asynchronous Transfer Mode (ATM) network or aFrame Relay network.
 24. The apparatus of claim 15, wherein the captureagent collects media packets in response to an alarm received by thecentral agent that indicates a potential error on the network.
 25. Asystem for identifying errors in a video conference conducted on apacket-based network, comprising: a first endpoint operable to couple tothe network and conduct the video conference, the first endpoint locatedin a first collision domain; a second endpoint operable to couple to thenetwork and conduct the video conference, the second endpoint located ina second collision domain; a central device operable to couple to thenetwork and distribute over the network a capture agent to a firstremote device associated with the first collision domain and a secondremote device associated with the second collision domain in response toreceiving a request to monitor the network during the video conference,each remote device operable to execute the capture agent, the captureagent operable to: collect a plurality of media packets associated withthe video conference; store the media packets in a first storage mediuminterfaced with the first remote device and a second storage mediuminterfaced with the second remote device until a timer expires; andcommunicate the media packets from the first and second storage mediumsto the central device when the timer expires.
 26. The system of claim25, wherein the central device comprises a central agent operable toanalyze the media packets at the central device to determine one or morenetwork parameters that caused an error in the video conference.
 27. Thesystem of claim 26, further comprising the network parameters selectedfrom the group consisting of latency, jitter, throughput, and packetloss.
 28. The system of claim 26, further comprising the requestreceived via an alarm generated by the central agent at the centraldevice, the alarm indicating a potential error on the network.
 29. Thesystem of claim 25, wherein the media packets comprise real timeprotocol (RTP) packets and real time control protocol (RTCP) packets.30. The system of claim 25, wherein the media packets comprise audioinformation.
 31. The system of claim 25, wherein the media packetscomprise video information.
 32. The system of claim 25, wherein themedia packets comprise data information.
 33. The system of claim 25,further comprising the request received from a system administrator atthe central device in response to a call from a user at either one ofthe first or second endpoints.
 34. The system of claim 25, furthercomprising the request received when a distribute timer expires.
 35. Thesystem of claim 25, wherein the timer expires after the capture agentcollects a predetermined number of media packets.
 36. The system ofclaim 25, further comprising: the first remote device located on a firstswitch port associated with the first collision domain, the first switchport operable to monitor network traffic between the two or moreendpoints within the first collision domain; and the second remotedevice located on a second switch port associated with the secondcollision domain, the second switch port operable to monitor networktraffic between the two or more endpoints within the second collisiondomain.
 37. A method for identifying errors in a video conferenceconducted on a packet-based network, comprising: receiving a request tomonitor the network during the video conference between two or moreendpoints; distributing a capture agent over the network from a centraldevice to each of the two or more endpoints in response to the request,the capture agent operable to collect a plurality of media packetstransmitted and received by the two or more endpoints during the videoconference; storing the media packets in storage mediums interfaced witheach of the two or more endpoints until the end of video conference;communicating the media packets from each of the storage mediums to thecentral device when the video conference ends; and analyzing the mediapackets at the central device to determine one or more networkparameters that caused the error.
 38. The method of claim 37, furthercomprising the network parameters selected from the group consisting oflatency, jitter, throughput, and packet loss.
 39. The method of claim37, wherein the media packets comprise real time protocol (RTP) packetsand real time control protocol (RTCP) packets.
 40. The method of claim37, wherein the media packets comprise audio information.
 41. The methodof claim 37, wherein the media packets comprise video information. 42.The method of claim 37, wherein receiving the request comprisesreceiving notification of a potential error on the network through analarm generated by a central agent located at the central device.
 43. Asystem for identifying errors in a video conference conducted on apacket-based network, comprising: means for receiving a request tomonitor the network during the video conference conducted between two ormore endpoints; means for distributing a capture agent over a networkfrom a central agent at a central device to a remote device in responseto the request, the remote device associated with a collision domainthat contains one of the two or more endpoints and operable to executethe capture agent; means for collecting a plurality of media packetsassociated with the video conference in a capture file until a timerexpires, the capture file located in a storage medium interfaced withthe remote device; and means for communicating the capture file from theremote device to the central device when the timer expires.